Re: [PATCH] mm/vmscan: Do not block forever atshrink_inactive_list().

[David Rientjes <rientjes@xxxxxxxxxx>]

On Mon, 26 May 2014, Tetsuo Handa wrote:

> In shrink_inactive_list(), we do not insert delay at
> 
>   if (!sc->hibernation_mode && !current_is_kswapd())
>     wait_iff_congested(zone, BLK_RW_ASYNC, HZ/10);
> 
> if sc->hibernation_mode != 0.
> Follow the same reason, we should not insert delay at
> 
>   while (unlikely(too_many_isolated(zone, file, sc))) {
>     congestion_wait(BLK_RW_ASYNC, HZ/10);
> 
>     /* We are about to die and free our memory. Return now. */
>     if (fatal_signal_pending(current))
>       return SWAP_CLUSTER_MAX;
>   }
> 
> if sc->hibernation_mode != 0.
> 
> Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
> ---
>  mm/vmscan.c |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)
> 
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 32c661d..89c42ca 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -1362,6 +1362,9 @@ static int too_many_isolated(struct zone *zone, int 
> file,
>       if (current_is_kswapd())
>               return 0;
>  
> +     if (sc->hibernation_mode)
> +             return 0;
> +
>       if (!global_reclaim(sc))
>               return 0;
>  

This isn't the only too_many_isolated() functions that do a delay, how is 
the too_many_isolated() in mm/compaction.c different?